﻿// DirectXUI.cpp : 定义应用程序的入口点。
//

#include "framework.h"
#include "DirectXUI.h"
#include "DeviceContext.h"
#include <wrl.h>
#include <Windowsx.h>
#include <dwmapi.h>

#pragma comment(lib, "dwmapi")

using Microsoft::WRL::ComPtr;

#define MAX_LOADSTRING 100

// 全局变量:
HINSTANCE hInst;                                // 当前实例
WCHAR szTitle[MAX_LOADSTRING];                  // 标题栏文本
WCHAR szWindowClass[MAX_LOADSTRING];            // 主窗口类名
DirectXUI::DeviceContext* deviceContext;

// 此代码模块中包含的函数的前向声明:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // TODO: 在此处放置代码。

    // 初始化全局字符串
    LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadStringW(hInstance, IDC_DIRECTXUI, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // 执行应用程序初始化:
    if (!InitInstance (hInstance, nCmdShow))
    {
        return FALSE;
    }

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_DIRECTXUI));

    MSG msg;

    // 主消息循环:
    while (GetMessage(&msg, nullptr, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}

//
//  函数: MyRegisterClass()
//
//  目标: 注册窗口类。
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_DIRECTXUI));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName = nullptr;
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassExW(&wcex);
}

//
//   函数: InitInstance(HINSTANCE, int)
//
//   目标: 保存实例句柄并创建主窗口
//
//   注释:
//
//        在此函数中，我们在全局变量中保存实例句柄并
//        创建和显示主程序窗口。
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // 将实例句柄存储在全局变量中

   auto desktopWnd = ::GetDesktopWindow();
   RECT desktopRect;
   ::GetWindowRect(desktopWnd, &desktopRect);
   auto width = 960;
   auto height = 594;
   auto left = (desktopRect.right - width) / 2;
   auto top = (desktopRect.bottom - height) / 2;

   HWND hWnd = CreateWindowEx(WS_EX_NOREDIRECTIONBITMAP,
       szWindowClass,
       szTitle, 
       WS_OVERLAPPEDWINDOW,
       left, 
       top,
       width,
       height,
       nullptr, 
       nullptr, 
       hInstance, 
       nullptr);

   if (!hWnd)
   {
      return FALSE;
   }

   //::SetWindowLong(hWnd, GWL_STYLE, ::GetWindowLong(hWnd, GWL_STYLE));

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

ComPtr<ID2D1SolidColorBrush> brush;

//
//  函数: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  目标: 处理主窗口的消息。
//
//  WM_COMMAND  - 处理应用程序菜单
//  WM_PAINT    - 绘制主窗口
//  WM_DESTROY  - 发送退出消息并返回
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_CREATE:
    {
        deviceContext = new DirectXUI::DeviceContext(hWnd);
        MARGINS margins = { -1 };
        ::DwmExtendFrameIntoClientArea(hWnd, &margins);
    }
        break;
    case WM_NCCALCSIZE:
    {
        return 0;
    }
        break;
    case WM_SIZE:
        deviceContext->CreateWindowSizeDependentResources();
        break;
    case WM_PAINT:
        {
            auto dc = deviceContext->GetD2DDeviceContext();

            dc->BeginDraw();
            dc->Clear();

            if (brush == nullptr)
                dc->CreateSolidColorBrush(D2D1_COLOR_F{ 
                .r = 0.0f,
                .g = 0.6f,
                .b = 0.0f, 
                .a = 1.0f }, brush.GetAddressOf());

            RECT rect;
            ::GetClientRect(hWnd, &rect);

            dc->FillRectangle(D2D1_RECT_F{ .left = 0.0f, .top = 0.0f, .right = (float)rect.right, .bottom = (float)rect.bottom }, brush.Get());

            dc->EndDraw();

            deviceContext->Present();
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    }

    return DefWindowProc(hWnd, message, wParam, lParam);
}

